From 928b66f1c897abbd10c19747556ee94ef8f41d5e Mon Sep 17 00:00:00 2001
From: Rob Woolley <rob.woolley@windriver.com>
Date: Tue, 26 Nov 2024 17:22:08 -0800
Subject: [PATCH] {common}{ros2} Add ROS opt prefix to PYTHONPATH

In order for Python to find modules in the recipe-sysroot
we must add the path to PYTHONPATH.  However, we must prepend
the path to any previous values of PYTHONPATH.

We cannot refer to the variable in its own definition since
bitbake does not evaluate strings in that way.

Instead we must mimick python3targetconfig.bbclass and
prepend to the recipe tasks to conditionally set PYTHONPATH
in the shell context.

Signed-off-by: Rob Woolley <rob.woolley@windriver.com>
---
 .../classes/ros_opt_prefix.bbclass            | 51 ++++++++++++++++++-
 meta-ros2/classes/ros_ament_cmake.bbclass     |  2 -
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/meta-ros-common/classes/ros_opt_prefix.bbclass b/meta-ros-common/classes/ros_opt_prefix.bbclass
index ac53ecea8c..db3117fa46 100644
--- a/meta-ros-common/classes/ros_opt_prefix.bbclass
+++ b/meta-ros-common/classes/ros_opt_prefix.bbclass
@@ -30,9 +30,56 @@ ROS_PYTHON_VERSION ?= "3"
 inherit ${@'python3-dir' if d.getVar('ROS_PYTHON_VERSION') == '3' else 'python-dir'}
 
 PKG_CONFIG_PATH .= ":${PKG_CONFIG_DIR}:${STAGING_DIR_HOST}${ros_libdir}/pkgconfig:${STAGING_DATADIR}/pkgconfig"
+
 PYTHON_SITEPACKAGES_DIR = "${ros_libdir}/${PYTHON_DIR}/site-packages"
-export PYTHONPATH = "${STAGING_DIR_NATIVE}${PYTHON_SITEPACKAGES_DIR}:$PYTHONPATH"
-PYTHONPATH:class-native = "${PYTHON_SITEPACKAGES_DIR}:$PYTHONPATH"
+
+setup_rosoptprefix_config() {
+        if [ -n "$PYTHON" ]; then export PYTHONPATH=${STAGING_DIR_NATIVE}${ros_libdir}/${PYTHON_DIR}/site-packages:$PYTHONPATH; fi
+}
+
+do_configure:prepend:class-target() {
+        setup_rosoptprefix_config
+}
+
+do_compile:prepend:class-target() {
+        setup_rosoptprefix_config
+}
+
+do_install:prepend:class-target() {
+        setup_rosoptprefix_config
+}
+
+setup_rosoptprefix_native_config() {
+        if [ -n "$PYTHON" ]; then export PYTHONPATH=${ros_libdir}/${PYTHON_DIR}/site-packages:$PYTHONPATH; fi
+}
+
+do_configure:prepend:class-native() {
+        setup_rosoptprefix_native_config
+}
+
+do_compile:prepend:class-native() {
+        setup_rosoptprefix_native_config
+}
+
+do_install:prepend:class-native() {
+        setup_rosoptprefix_native_config
+}
+
+setup_rosoptprefix_nativesdk_config() {
+        if [ -n "$PYTHON" ]; then export PYTHONPATH=${STAGING_DIR_NATIVE}${ros_base_prefix}/lib/${PYTHON_DIR}/site-packages:$PYTHONPATH; fi
+}
+
+do_configure:prepend:class-nativesdk() {
+        setup_rosoptprefix_nativesdk_config
+}
+
+do_compile:prepend:class-nativesdk() {
+        setup_rosoptprefix_nativesdk_config
+}
+
+do_install:prepend:class-nativesdk() {
+        setup_rosoptprefix_nativesdk_config
+}
 
 FILES_SOLIBSDEV += " ${ros_libdir}/lib*${SOLIBSDEV}"
 
diff --git a/meta-ros2/classes/ros_ament_cmake.bbclass b/meta-ros2/classes/ros_ament_cmake.bbclass
index 64eedb4590..42a9b147d7 100644
--- a/meta-ros2/classes/ros_ament_cmake.bbclass
+++ b/meta-ros2/classes/ros_ament_cmake.bbclass
@@ -26,8 +26,6 @@ export AMENT_PREFIX_PATH="${STAGING_DIR_HOST}${prefix};${STAGING_DIR_NATIVE}${pr
 
 inherit cmake python3native
 
-PYTHONPATH:prepend:class-nativesdk = "${STAGING_DIR_NATIVE}${ros_base_prefix}/lib/python${PYTHON_BASEVERSION}/site-packages:"
-
 FILES:${PN}:prepend = " \
     ${datadir}/ament_index \
 "